A: 425
B: 850
C: 1275
D: 11275
The organization Wild Aid is _________ to protect wild animals. ——It has done a lot so far.
有一抛物线型拱桥,当水面离拱顶2米时,水面宽4米,则当水面下降1米后,水面宽度为( )
下列句子中划线词语运用无误的一项是( )